Benchmarking a Non-Equilibrium Approach to Photon Emission in Relativistic Heavy-Ion Collisions

Abstract

In this work, the production of photons through binary scattering processes is investigated for equilibrated hadronic systems. More precisely, a non-equilibrium hadronic transport approach to describe relativistic heavy-ion collisions is benchmarked with respect to photon emission. Cross sections for photon production in $\pi +\rho \to \pi +\gamma$ and $\pi +\pi \to \rho +\gamma$ scattering processes are derived from an effective chiral field theory and implemented into the hadronic transport approach, SMASH (Simulating Many Accelerated Strongly-interacting Hadrons). The implementation is verified by systematically comparing the thermal photon rate to theoretical expectations. Further, the impact of form factors is discussed, scattering processes mediated by $\omega$ mesons are found to contribute significantly to the total photon production. Several comparisons of the yielded photon rates are performed: to parametrizations of the very same rates, as used in hydrodynamic simulations, to previous works relying on different cross sections for the production of direct photons from the hadronic stage, and to partonic rates. Finally, the impact of considering the finite width of the $\rho$ meson is investigated, where a significant enhancement of photon production in the low-energy region is observed. This benchmark is the first step towards a consistent treatment of photon emission in hybrid hydrodynamics+transport approaches and a genuine dynamical description.

arXiv comment14 pages, 15 figures

References in corpus (42)

• Big-Bang Nucleosynthesis
• 3+1D hydrodynamic simulation of relativistic heavy-ion collisions
• Photon Emission from Quark-Gluon Plasma: Complete Leading Order Results
• Photon Emission from Ultrarelativistic Plasmas
• Enhanced production of direct photons in Au+Au collisions at sqrt(s_NN)=200 GeV and implications for the initial temperature
• The importance of the bulk viscosity of QCD in ultrarelativistic heavy-ion collisions
• Particle production and equilibrium properties within a new hadron transport approach for heavy-ion collisions
• The production of photons in relativistic heavy-ion collisions
• Hadronic Production of Thermal Photons
• Direct photon production in Pb-Pb collisions at $\sqrt{s_\rm{NN}}$ = 2.76 TeV
• Observation of direct-photon collective flow in sqrt(s_NN)=200 GeV Au+Au collisions
• Conformal anomaly as a source of soft photons in heavy ion collisions
• Thermal Photons and Collective Flow at the Relativistic Heavy-Ion Collider
• Measurement of Direct Photons in pp and Pb-Pb Collisions with ALICE
• Effective QCD and transport description of dilepton and photon production in heavy-ion collisions and elementary processes
• Thermal photons as a quark-gluon plasma thermometer revisited
• Azimuthally anisotropic emission of low-momentum direct photons in Au$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV
• Pseudo-Critical Enhancement of Thermal Photons in Relativistic Heavy-Ion Collisions
• Measurement of Direct-Photon Elliptic Flow in Pb-Pb Collisions at sqrt(NN) = 2.76 TeV
• Production and Elliptic Flow of Dileptons and Photons in the semi-Quark Gluon Plasma
• Landau-Pomeranchuk-Migdal effect in thermal field theory
• Viscous photons in relativistic heavy ion collisions
• Centrality dependence of the direct photon yield and elliptic flow in heavy-ion collisions at sqrt(s)=200 GeV
• Shear viscosity of a hadron gas and influence of resonance lifetimes on relaxation time
• Elliptic flow from thermal photons with magnetic field in holography
• Anisotropy of photon production: Initial eccentricity or magnetic field
• Thermal photon $v_2$ with slow quark chemical equilibration
• Direct photon elliptic flow in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Universal Parametrization of Thermal Photon Rates in Hadronic Matter
• Low-Energy Thermal Photons from Meson-Meson Bremsstrahlung
• Dilepton production and resonance properties within a new hadronic transport approach in the context of the GSI-HADES experimental data
• Elliptic flow of thermal photons in heavy-ion collisions at Relativistic Heavy Ion Collider and Large Hadron Collider
• A Tale of Tails: Photon Rates and Flow in Ultra-Relativistic Heavy Ion Collisions
• Thermal photon emission from the pi-rho-omega system
• Nonequilibrium photon production in partonic transport simulations
• Electrical conductivity and relaxation via colored noise in a hadronic gas
• Elliptic flow of thermal photons in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV
• Hybrid model calculations of direct photons in high-energy nuclear collisions
• Equilibration and freeze-out of an expanding gas in a transport approach in a Friedmann-Robertson-Walker metric
• Elliptic flow of thermal dileptons as a probe of QCD matter
• Probing the spacetime evolution of heavy ion collisions with photons and dileptons
• Direct photon production in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV at STAR

Cited by in corpus (17)

• Multi-messenger heavy-ion collision physics
• (3+1)-D viscous hydrodynamics CLVisc at finite net baryon density: identified particle spectra, anisotropic flows and flow fluctuations across BES energies
• The Present and Future of QCD
• The QCD phase diagram and Beam Energy Scan physics: a theory overview
• Local and global polarization of $\Lambda$ hyperons across RHIC-BES energies: the roles of spin hall effect, initial condition and baryon diffusion
• Particle production in a hybrid approach for a beam energy scan of Au+Au/Pb+Pb collisions between $\sqrt{s_{\mathrm{NN}}}$ = 4.3 GeV and $\sqrt{s_{\mathrm{NN}}}$ = 200.0 GeV
• The emission of electromagnetic radiation from the early stages of relativistic heavy-ion collisions
• Photon production and elliptic flow from momentum-anisotropic quark-gluon plasma
• Prompt, pre-equilibrium, and thermal photons in relativistic nuclear collisions
• The applicability of hydrodynamics in heavy ion collisions at $\sqrt{s_{\mathrm{NN}}}$= 2.4-7.7 GeV
• Some Aspects of the Theory of Heavy Ion Collisions
• Particle Production in AgAg Collisions at $E_{\mathrm{Kin}}=1.58A$ GeV within a Hadronic Transport Approach
• Direct Photons in Hydrodynamic Modeling of Relativistic Nuclear Collisions
• A Non-Equilibrium Approach to Photon Emission from the Late Stages of Relativistic Heavy-Ion Collisions
• System size and shape dependences of collective flow fluctuations in relativistic nuclear collisions
• Geometrical Scaling of Direct Photons in Relativistic Heavy Ion and d+Au Collisions
• Transport Model Comparison Studies of Intermediate-Energy Heavy-Ion Collisions